Modeling of a Magneto-Rheological Damper Using System Identification

2010 ◽  
Author(s):  
Sudhir Kaul
Keyword(s):  
System Identification ◽  
Mr Damper ◽  
Operating Conditions ◽  
Parametric Models ◽  
Model Parameters ◽  
Recursive Models ◽  
Recursive System ◽  
Set Up ◽  
Magneto Rheological ◽  
Improved Model

This paper proposes the use of three recursive system identification techniques for modeling a magneto-rheological (MR) damper. The results of the three models are compared to one another and to two parametric models that have been commonly used in the existing literature for modeling MR dampers. An MR damper has been built in-house and an experimental set-up has been fabricated as part of this work. The set-up is used for data collection and the data is used for building the recursive models. The results from the system identification models are compared to the measured data as well as to the parametric models. While the parametric models are seen to work well within limited bounds of input variables and operating conditions, these models can be used outside the range of these bounds only after carrying out a new characterization of the model parameters. The recursive system identification models, on the other hand, continuously update all model parameters as and when data becomes available, as demonstrated by the three recursive models presented in this paper. The advantages of the recursive models are conclusively established by lower measures of error, a better representation of hysteresis and saturation phenomena exhibited by the MR damper and significantly improved model tracking. This is a major improvement over the commonly used parametric models, thereby making the recursive models specifically conducive to adaptive control algorithms.

A Non Parametric Model for Magneto Rheological Dampers

1999 ◽  
Author(s):  
Mehdi Ahmadian ◽  
Xubin Song
Keyword(s):  
Test Data ◽  
Mr Damper ◽  
Parametric Model ◽  
Parametric Models ◽  
Magnetic Saturation ◽  
Mr Dampers ◽  
Electro Magnetic ◽  
Magneto Rheological ◽  
Force Characteristics ◽  
Non Parametric

Abstract A non-parametric model for magneto-rheological (MR) dampers is presented. After discussing the merits of parametric and non-parametric models for MR dampers, the test data for a MR damper is used to develop a non-parametric model. The results of the model are compared with the test data to illustrate the accuracy of the model. The comparison shows that the non-parametric model is able to accurately predict the damper force characteristics, including the damper non-linearity and electro-magnetic saturation. It is further shown that the parametric model can be numerically solved more efficiently than the parametric models.

Application of an Improved Streamline Curvature Approach to a Modern, Two-Stage Transonic Fan: Comparison With Data and CFD

2002 ◽  
Author(s):  
Keith M. Boyer ◽  
Walter F. O’Brien
Keyword(s):  
Three Dimensional ◽  
Operating Conditions ◽  
Navier Stokes ◽  
Model Parameters ◽  
Two Stage ◽  
Streamline Curvature ◽  
Wide Range ◽  
Improved Model ◽  
Transonic Fan ◽  
Streamline Curvature Method

A streamline curvature method with improvements to key loss models is applied to a two-stage, low aspect ratio, transonic fan with design tip relative Mach number of approximately 1.65. Central to the improvements is the incorporation of a physics-based shock model. The attempt here is to capture the effects of key flow phenomena relative to the off-design performance of the fan. A quantitative analysis regarding solution sensitivities to model parameters that influence the key phenomena over a wide range of operating conditions is presented. Predictions are compared to performance determined from overall and interstage measurements, as well as from a three-dimensional, steady, Reynolds-averaged Navier-Stokes method applied across the first rotor. Overall and spanwise comparisons demonstrate that the improved model gives reasonable performance trending and generally accurate results. The method can be used to provide boundary conditions to higher-order solvers, or implemented within novel approaches using the streamline curvature method to explore complex engine-inlet integration issues, such as time-variant distortion.

Semi-Active Control of a Vehicle Suspension Based on Magneto-Rheological Damper

2011 ◽  
Vol 311-313 ◽  
pp. 2286-2290
Author(s):  
Jie Lai Chen ◽  
Xue Zheng Jiang ◽  
Ning Xu
Keyword(s):  
Ride Comfort ◽  
Mr Damper ◽  
Vehicle Suspension ◽  
Damping Force ◽  
Mr Dampers ◽  
Quarter Car ◽  
Set Up ◽  
Magneto Rheological ◽  
Two Degree Of Freedom ◽  
The Magnetic Field

The focus of this study is to experimentally investigate a semi-active magneto-rheological (MR) damper for a passenger vehicle, by using a quarter car models. After verifying that the damping force of the MR damper can be continuously tuned by the intensity of the magnetic field, a full-scale two-degree of freedom quarter car experimental set up is constructed to study the vehicle suspension. On-off skyhook controller is employed to achieve the desired damping force. The experimental results show that the semi-active vehicle suspension vibration control system based on MR dampers is feasible and can effectively improve ride comfort of vehicle.

Magneto-Rheological (MR) Damper Modeling for Semi-Active Control Without Force Feedback

2012 ◽  
Author(s):  
Anria Strydom ◽  
Pieter S. Els ◽  
Sudhir Kaul
Keyword(s):  
Active Control ◽  
Ride Comfort ◽  
Mr Damper ◽  
Parametric Model ◽  
Model Parameters ◽  
Damping Force ◽  
Recursive Model ◽  
Online Identification ◽  
Handling Characteristics ◽  
Magneto Rheological

Ride comfort and handling characteristics are two important aspects of vehicle dynamics that generally require contrasting suspension settings. Different damper settings of the suspension system are required in order to meet these conflicting requirements. A magneto-rheological (MR) damper allows variable suspension settings to achieve enhanced ride comfort as well as handling characteristics by providing adaptable damping. Implementation of semi-active control requires an accurate MR damper model and online identification of model parameters. However, modeling a MR damper for a wide range of input conditions is challenging, especially when there are constraints on necessary measurements that are required for modeling. Although the available literature proposes various parametric models, many of these models are computationally expensive and are not viable for online identification. This paper presents a non-parametric model as well as a recursive model to predict the damping force of a MR damper in order to implement a semi-active control algorithm on an off-road vehicle. The results of the two models are compared to a conventional parametric model. The recursive model is used to demonstrate the significance of including the measured damping force in the model. Whereas the availability of the measured damping force yields a reasonably accurate model, the lack of measured damping force significantly impairs the recursive model.

Dynamic and Control of Vibratory Road Roller Based on Magneto-Rheological Semi-Active Damper

2012 ◽  
Vol 479-481 ◽  
pp. 1200-1204 ◽  
Author(s):  
Shao Na Liu ◽  
Shi Rong Yan ◽  
Shu Wei Li ◽  
Yao Gang Zheng
Keyword(s):  
Fuzzy Control ◽  
Dynamic Characteristic ◽  
Control Strategy ◽  
Mr Damper ◽  
Actual Situation ◽  
Important Research ◽  
Set Up ◽  
Magneto Rheological ◽  
Active Damper ◽  
And Control

Comfort of the vibratory road roller is an important research title. A 2-DOF non-line model is set up, which is more close to the actual situation of the vibratory road roller. A simulation using MATLAB/SIMULINK is carried out to validate this model and study its dynamic characteristic and analyze the motion laws of its housing and wheel. A kind of Magneto-rheological (MR) damper is designed which has been widely used in automotive and bridge damping in recent years, and applied to a vibratory road roller to control it. The control strategy uses fuzzy control. The results indicate that the damping performance of the vibratory road roller which applied MR damper is improved remarkably.

scholarly journals ARX Linear Model Set-Up for Fault Diagnosis of Gas Turbine Sensors

1997 ◽  
Author(s):  
R. Bettocchi ◽  
P. R. Spina
Keyword(s):  
Fault Diagnosis ◽  
System Identification ◽  
Gas Turbine ◽  
Linear Model ◽  
Time Series Data ◽  
System Modeling ◽  
Series Data ◽  
Model Parameters ◽  
Model Set ◽  
Set Up

The diagnosis of gas turbine sensor faults requires models of the system to calculate estimates of the measured output system variables. The model set-up phase is of great importance since the reliability of the diagnostic tool depends on the model accuracy. In the paper two different methodologies of I/O linear model set-up are analyzed and compared to find the more simple and general one. The first methodology consists in obtaining the I/O linear models by directly linearizing the physical laws (system modeling). The second one uses statistical methods (system identification) to calculate model parameters from time series data measured on the machine. The models used are of the ARX (Auto Regressive with eXternal input) type. The number of models and the measured variables correlated by each of them have been determined in order to obtain unambiguous fault signatures for each sensor. The system identification method proves to be more suitable to the system modeling because of its greater simplicity in the fault diagnosis application.

Research on Vibration Isolating with Magneto-Rheological Damper

2011 ◽  
Vol 328-330 ◽  
pp. 2190-2193
Author(s):  
Zhao Wang Xia ◽  
Xiao Min Qi ◽  
Hua Bing Wen
Keyword(s):  
Vibration Isolation ◽  
Passive Control ◽  
Mechanical Response ◽  
Mr Damper ◽  
Model Parameters ◽  
Test Model ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Proposed Model ◽  
Magneto Rheological

This work presents a test model of a vibration isolation system with magneto-rheological (MR) damper, and the Bingham model to describe the dynamic process of mechanical response for the MR damper. The analytical solution of the system in passive control is obtained via the averaging method, and verified numerically. The parameters which affect the performance of the vibration isolation are adjusted appropriately; the effects of the parameter are quantitatively or qualitatively analyzed.The proposed model utilizes a method that can be employed in a variety of dynamic systems. Moreover, the model parameters have direct physical significance to the MRF damper properties.

Damping characteristics of a magneto-rheological damper with dual independent controllable ducts

2021 ◽  
pp. 1045389X2110188
Author(s):  
Jianqiang Yu ◽  
Xiaomin Dong ◽  
Tao Wang ◽  
Zhengmu Zhou ◽  
Yaqin Zhou
Keyword(s):  
Dynamic Range ◽  
Fluid Flows ◽  
Mr Damper ◽  
Viscous Damping ◽  
The Novel ◽  
The Finite Element Method ◽  
Damping Force ◽  
Damping Characteristics ◽  
Magneto Rheological ◽  
The Mathematical Model

This paper presents the damping characteristics of a linear magneto-rheological (MR) damper with dual controllable ducts based on numerical and experimental analysis. The novel MR damper consisting of a dual-rod cylinder system and a MR valve is used to reduce the influences of viscous damping force and improve dynamic range. Driven by the dual-rod cylinder system, MR fluid flows in the MR valve. The pressure drop of the MR valve with dual independent controllable ducts can be controlled by tuning the current of two independent coils. Based on the mathematical model and the finite element method, the damping characteristics of the MR damper is simulated. A prototype is designed and tested on MTS machine to evaluate its damping characteristics. The results show that the working states and damping force of the MR damper can be controlled by the two independent coils.

scholarly journals Modeling Bacterial Regrowth and Trihalomethane Formation in Water Distribution Systems

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 463
Author(s):  
Gopinathan R. Abhijith ◽  
Leonid Kadinski ◽  
Avi Ostfeld
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Mechanistic Model ◽  
Water Distribution Systems ◽  
Sensitivity Study ◽  
Operating Conditions ◽  
Growth Rate Constant ◽  
Model Parameters ◽  
Bacterial Regrowth ◽  
The Impact

The formation of bacterial regrowth and disinfection by-products is ubiquitous in chlorinated water distribution systems (WDSs) operated with organic loads. A generic, easy-to-use mechanistic model describing the fundamental processes governing the interrelationship between chlorine, total organic carbon (TOC), and bacteria to analyze the spatiotemporal water quality variations in WDSs was developed using EPANET-MSX. The representation of multispecies reactions was simplified to minimize the interdependent model parameters. The physicochemical/biological processes that cannot be experimentally determined were neglected. The effects of source water characteristics and water residence time on controlling bacterial regrowth and Trihalomethane (THM) formation in two well-tested systems under chlorinated and non-chlorinated conditions were analyzed by applying the model. The results established that a 100% increase in the free chlorine concentration and a 50% reduction in the TOC at the source effectuated a 5.87 log scale decrement in the bacteriological activity at the expense of a 60% increase in THM formation. The sensitivity study showed the impact of the operating conditions and the network characteristics in determining parameter sensitivities to model outputs. The maximum specific growth rate constant for bulk phase bacteria was found to be the most sensitive parameter to the predicted bacterial regrowth.

scholarly journals Determination of synchronous generator nonlinear model parameters based on power rejection tests using a gradient optimization algorithm

2017 ◽  
Vol 65 (4) ◽  
pp. 479-488 ◽  
Author(s):  
A. Boboń ◽  
A. Nocoń ◽  
S. Paszek ◽  
P. Pruski
Keyword(s):  
Parameter Estimation ◽  
Objective Function ◽  
Optimization Algorithm ◽  
Least Squares Method ◽  
Synchronous Generator ◽  
Operating Conditions ◽  
Model Parameters ◽  
State Variables ◽  
Starting Point ◽  
Gradient Optimization

AbstractThe paper presents a method for determining electromagnetic parameters of different synchronous generator models based on dynamic waveforms measured at power rejection. Such a test can be performed safely under normal operating conditions of a generator working in a power plant. A generator model was investigated, expressed by reactances and time constants of steady, transient, and subtransient state in the d and q axes, as well as the circuit models (type (3,3) and (2,2)) expressed by resistances and inductances of stator, excitation, and equivalent rotor damping circuits windings. All these models approximately take into account the influence of magnetic core saturation. The least squares method was used for parameter estimation. There was minimized the objective function defined as the mean square error between the measured waveforms and the waveforms calculated based on the mathematical models. A method of determining the initial values of those state variables which also depend on the searched parameters is presented. To minimize the objective function, a gradient optimization algorithm finding local minima for a selected starting point was used. To get closer to the global minimum, calculations were repeated many times, taking into account the inequality constraints for the searched parameters. The paper presents the parameter estimation results and a comparison of the waveforms measured and calculated based on the final parameters for 200 MW and 50 MW turbogenerators.

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